I see! By the way, do you know how to fix the @DIN cannot be applied correctly after you subtract your data from @AVE?
I need to calculate the mass transported by Hadley cells. So my v-wind must be zero when integrating through the whole column. Usually, it can be solved by subtracting the average value of v-wind. During my process of subtracting the average values, I found if you subtract the average value, pyferret does NOT treat your new values as "spatial data" (I don't know how to describe it). For example,
set data coads_climatology
let test=SST[L=8] ! just a random month
let mean=test[I=@AVE,J=@AVE]
list mean
VARIABLE : TEST[I=@AVE,J=@AVE]
FILENAME : coads_climatology.cdf
FILEPATH : /home/xbai1/miniconda2/envs/FERRET/share/fer_dsets/data/
LONGITUDE: 20E to 20E(380)
LATITUDE : 90S to 90N
TIME : 16-AUG 07:23
21.16
which means the average value is 21.16 Celsius. Then I do:
let comp1=test-mean
let comp2=test-21.16
let bad_din=comp1[I=@DIN,J=@DIN]
let good_din=comp2[I=@DIN,J=@DIN]
list bad_din, good_din
DATA SET: /home/xbai1/miniconda2/envs/FERRET/share/fer_dsets/data/coads_climatology.cdf
LONGITUDE: 20E to 20E(380)
LATITUDE: 90S to 90N
TIME: 16-AUG 07:23
Column 1: BAD_DIN is COMP1[I=@DIN,J=@DIN]
Column 2: GOOD_DIN is COMP2[I=@DIN,J=@DIN]
BAD_DIN GOOD_DIN
I / *: -91.65 -2.954E+11
show grid comp1, comp2
GRID GSQ1
name axis # pts start end subset
COADSX LONGITUDE 180mr 21E 19E(379) full
COADSY LATITUDE 90 r 89S 89N full
normal Z
TIME TIME 12mr 16-JAN 06:00 16-DEC 01:20 1 pt
GRID GSQ1
name axis # pts start end subset
COADSX LONGITUDE 180mr 21E 19E(379) full
COADSY LATITUDE 90 r 89S 89N full
normal Z
TIME TIME 12mr 16-JAN 06:00 16-DEC 01:20 1 pt
Looks like to me, the new value after subtracting @AVE was treated like pure numeric values. But it's not @SUM type of calculation.
list comp1[I=@SUM,J=@SUM], comp2[I=@SUM,J=@SUM]
DATA SET: /home/xbai1/miniconda2/envs/FERRET/share/fer_dsets/data/coads_climatology.cdf
LONGITUDE: 20E to 20E(380) (XY summed)
LATITUDE: 90S to 90N (XY summed)
TIME: 16-AUG 07:23
Column 1: COMP1 is TEST-MEAN
Column 2: COMP2 is TEST-21.16
COMP1 COMP2
I / *: -17139. -17147.
I am puzzled by this issue.
Thank you very much and stay healthy,
Xiaoyu